Without vaccine, child 18 to 28 times more likely to be diagnosed, researchers say.

A report published in Tuesday's Journal of the American Medical Association highlights the need for people to be up to date on the vaccine to protect against pertussis, also known as "whooping cough."

Researchers in Denver said for every child who missed a dose of diphtheria, tetanus and acellular pertussis vaccine, or DTaP vaccine, the child was 18 to 28 times more likely to be diagnosed with pertussis than compared to others who were vaccinated.

Oklahoma state health officials encourage women who are pregnant to get the DTaP vaccine in the last trimester of pregnancy. This is because health officials found when a woman receives the shot, she passes on the protection to the unborn baby.

According to medical officials, newborns are particularly vulnerable to whooping cough. Newborns are first eligible for the vaccine at 2 months old.

In Texas, where 2000 cases were reported this year alone, two of the cases were deadly. Both of the victims were under 2 months old.

Oklahoma state health officials report far fewer cases than Texas. There are 99 reported cases in Oklahoma this year, 33 of those are in Tulsa. There were 159 cases last year.

The state is not just encouraging expectant mothers to get a booster shot, but anyone who will come in contact with a newborn: the spouse or partner of the mother, family members or caregivers who will help care for the baby can often be carriers of the bacteria.

The hope of health officials is that this latest warning will encourage people to stay up to date on the vaccines.

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